In recent years, various structures have been provided to form a portable sheet bending brake for bending metal or plastic sheets such as are used in siding on homes and buildings. Typical patents comprise U.S. Pat. Nos. 3,161,223, 3,481,174, 3,482,427, 3,559,444, 3,817,075, 3,872,755 and 4,321,817.
Such brakes comprise a fixed member on which the sheet is clamped and a movable bending member for bending the sheet. A major problem with respect to such sheet bending brakes is the tendency of the bending member to move relative to the portion of the sheet being bent and thereby mar the surface of the sheet.
In U.S. Pat. No. 3,161,223, the tendency to mar the surface of the sheet material was minimized by having the intermeshing integral projections between the fixed member and bending member which extend longitudinally and define the hinge that connects the bending member with the fixed member having the clamping surface, positioned so that all portions of the projections do not extend above the plane of the surface of the members when the surfaces are substantially aligned.
U.S. Pat. Nos. 3,481,174 and 3,482,427 were directed to an arrangement which included a floatable compensator on the bending member which engages the sheet material and as the bending member is swung to bend the sheet pivots so that the contact with the sheet material is maintained.
In U.S. Pat. No. 4,557,132 there is disclosed and claimed a sheet bending brake that incorporates a novel construction for minimizing the marring of the surface of the sheet material during bending; which functions without the need for added parts; which can be manufactured at low cost; and which can be adapted to sheet material of various thickness; and which can be utilized in a novel fashion to provide a complete 180.degree. bend to the sheet material.
As described in the aforesaid patent, each of the fixed and movable bending members have substantially the entire length of the longitudinal edges thereof formed with longitudinally spaced intermeshing integral projections. The projections on the bending member having a plurality of aligned openings and the projections on the fixed member have a plurality of aligned openings comprising slots extending axially with respect to the longitudinal axis of said member. A hinge pin extends through the openings of said bending member and the slots of the fixed member. The slots have a configuration such that as the bending member is moved relative to the fixed member to bend a workpiece, the hinge pin is guided along said slots such that the contacting portion of the bending member remains substantially in the same position relative to the workpiece.
In the use of such portable sheet metal bending brakes, it is sometimes necessary to cut a workpiece while the workpiece is clamped in the sheet metal bending brakes. As far as is known, the only way now used is to use a utility knife to score the workpiece and then bend the work piece back and forth along the score line.
Such a method results in edges that are not accurate, not smooth and not flat. This manner of cutting leaves a rolled edge. In addition, it is time consuming. Furthermore, there is serious risk of marring the aluminum parts of the brake which include the clamping surface, clamping member, bending member and hinge. As a result, the repeated use of the utility knife eventually cuts the edges of the clamping member and may eventually severely damages and cut through the hinge. This reduces the useful life of the portable sheet bending brake.
Among the objectives of the present invention are to provide a portable bending brake and hand operated cutter system that is removably mounted on a portable sheet bending brake; which will accurately cut the workpiece; which requires a minimal modification of the portable sheet bending brake; which can be readily added to an existing portable sheet bending brake; which will provide accurate, smooth and flat edges on the workpiece; which cuts the workpiece quickly and is therefore time saving; which does not damage the aluminum parts of the portable sheet bending brake; and which is low in cost.
In accordance with the invention, the portable sheet bending brake includes a track mounted on either the clamping member, the bending member or the clamping handle and a removable cutter having cutting rolls thereon engaging said track and manually movable longitudinally of the track to cut a workpiece clamped in the portable sheet bending brake. In one form, the track is on the clamping member of the portable sheet bending brake and the rollers on the cutter engage the track. A second set of rollers of the cutter engage another portion of the clamping member so that the cutter is mounted in cantilever fashion on the clamping member. In another form, the track is on the C-shaped members that support the clamping members and are constructed and arranged to mount the cutter in cantilever fashion. In another form, the track on the clamping member is removably mounted on the clamping member. In a further form, the track is mounted on the bending member. In another form, the track is hinged to the bending brake.